Yeah thats where we are heading eventually... but since cash is tight at the moment we were hoping that we could add the X charger on its own, still restricted by the current IC and intake, and that would give us a boost, then we could unlock its potential as funds became available.

Is there a definite answer on the requirement for 42lb injectors if the SC is added on its own?

If you go with the X charger (excellent choice by the way) the 42lb injectors will work fine. If you were to add the green wheel and new washers,etc. you would almost be at the price of the X charger--and the X charger not only gives more boost, but an increase in volume of air.